Synthesis and Characterization of Iron-doped TiO2 Immobilized on to Cellulosic Nanocomposite for the removal of Organic Contaminants

Abstract

In the processing of textile dyes and pharmaceutical compounds, large amount of waste is generated which directly or indirectly gets disposed-off into water streams. This has led to the undesirable toxicity of surface as well as ground water inducing negative impact on organisms residing in aquatic water bodies and humans. Therefore, it becomes necessary to efficiently remove these organic compounds from municipal as well as industrial effluents. In view of the aforementioned requirement heterogeneous photocatalysis act as cost-effective approach in lieu of conventional wastewater treatment technologies. In present study, TiO2 (Titanium dioxide) nanoparticles were synthesized chemically using solution route. As TiO2 is active only under Ultraviolet (UV) exposure, doping with iron (Fe) is performed to alter its surface properties and make it visible light responsive. To further improve its separation and reusability the doped TiO2 is mixed with biodegradable support matrix i.e. microcrystalline cellulose (MC). The synthesized bionanocomposite was characterized through Diffuse Reflectance Spectroscopy (DRS), Dynamic Light Scattering (DLS), X-Ray Diffraction Spectroscopy (XRD), Zeta Potential(ZP), Brunauer-Emmett-Teller(BET), Fourier-infrared Transform Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Analysis(EDX) to study their surface and morphological properties. The resulting bionanocomposite showed a significant photocatalytic degradation of methylene blue ~95% and diclofenac ~84% within 120 minutes of solar irradiation. Reusability tests were carried out in order to check the economic viability of bionanocomposite which was found to be 49% even after 8 consecutive uses. Kinetics of photocatalytic degradation was modelled against different equations in order to elucidate the trend of degradation which was found to be pseudo-first order. Thus this study suggested the use of Fe-TiO2-cellulose as a green and sustainable catalyst for wastewater treatment without leaving any photocatalyst in the reaction system hence contributing towards use of green technology system.